Gastrointestinal (GI), urogenital, and respiratory illnesses remain major public health problems. In the United States alone, about 650,000 persons are diagnosed with GI tract and urogenital cancers (tongue, esophageal, gastric, small intestine, colorectal, anal, bladder, pancreatic, kidney/renal, prostate, testicular, cervical and ovarian cancers) each year, resulting in about 200,000 deaths. Another 40 million are diagnosed with respiratory illnesses such as pneumonia, lung cancer, asthma, bronchitis, emphysema, and cystic fibrosis. Food poisoning incidence from all causes is about 76 million resulting in about 5,000 deaths. Other GI tract disorders such as inflammatory bowel disease, including ulcerative colitis and Crohn's disease, affect 1.4 million Americans.
Current treatments are insufficient for many of these diseases and disorders. Increased residence time in a particular region of the gastrointestinal (GI) tract would greatly improve the therapeutic benefit of many orally administered pharmaceuticals (Davis, S. S. Drug Discovery Today 10, 249-57, 2005). Controlling GI residence may also provide oral administration of therapeutics that currently are administered by injection (Chen, H. M., Langer, R. Pharm. Res. 14, 537-540, 1997; Goldberg, M., Gomez-Orellana, I. Nat. Rev. Drug Discovery 2, 289-95, 2003; Langer, R. Nature 392, 5-10 Suppl. S, 1998; Mathiowitz, E. et. al. Nature 386, 410-14, 1997; Whitehead, K., Shen, Z. C., Mitragotri, S. J. Controlled Release 98, 37-45, 2004), a benefit for cost savings and comfort of those affected by these diseases.